With increased age comes increased likelihood of disability as people live longer and do not encounter fatal diseases. Unfortunately, this positive association between age and disability sometimes leads to a negative image of aging. Disability occurs when physical or mental health declines associated with aging, illness, or injury restrict ability to perform activities of daily living. This chapter discusses the effect of disability on biopsychosocial functioning throughout the lifespan, the effect of culture, race, and ethnicity on behaviors, attitudes, and identity, and the effects of discrimination and stereotypes on behaviors, attitudes, and identity. It describes the influence of sexual orientation on behaviors, attitudes, and identity, the impact of transgender and transitioning process on behaviors, attitudes, identity, and relationships, and the principles of culturally competent social work practice. The chapter ends with discussion of sexual orientation concepts and gender and gender identity concepts.